puzzle

puzzle.hx

class Collection {
	var arr:Array<Int>;
	var i:Int = 0;

	public function new(arr:Array<Int>) {
		this.arr = arr;
	}

	public var current(get, set):Int;
	function get_current():Int { return arr[i]; }
	function set_current(v:Int):Int { return arr[i] = v; }

	public function next():Void { if (hasNext()) i++; }
	public function prev():Void { if (hasPrev()) i--; }
	public function hasNext():Bool { return i < arr.length - 1; };
	public function hasPrev():Bool { return i > 0; };
}

class Test {
	static function main() {
		var originalArray = [10, 5, 0];
		var collection = new Collection(originalArray);
		sum(collection);
		//Last number should be a sum of first two numbers
		trace(originalArray[originalArray.length - 1]);
	}

	static function sum(collection:Collection):Void {
		//Can only write your code inside the body of this function
		//Can't change signature of this function
		//No variable definitions are allowed at all
	}
}